In this frothy fantasy thriller from bestseller Connolly (The Book of Lost Things ), 11-year-old Samuel Johnson witnesses an inadvertent intersection of science and the supernatural while trick-or-treating at the Abernathy household in Biddlecombe, England. Something nasty reaches through an atomically engineered portal to Hades and possesses four suburban sorcerers. From that point on, Samuel finds himself battling hordes of invading demons and desperately trying to convince disbelieving adults that the impending end of the world is not a fancy of his overactive imagination. Connolly plays this potentially spooky scenario strictly for laughs, larding the narrative with droll jokes, humorous asides and the slapstick pratfalls of Nurd, an amusingly incompetent subdemon whom Samuel ultimately befriends. Though billed as “an adult book for children,” this light fantasy will strike even adult readers as divertingly whimsical. (Oct.)